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Table Of Contents
RSVP Bandwidth Allocation and Modular QoS Command Line Interface (CLI)
Related Features and Technologies
Supported Standards, MIBs, and RFCs
Defining ATM QoS Traffic Parameters for a PVC
Applying a Policy Map to a PVC
Verifying RSVP Support for ATM/PVCs Configuration
Monitoring and Maintaining RSVP Support for ATM/PVCs
RSVP Support for ATM/PVCs
This document describes Cisco Resource Reservation Protocol (RSVP) support for the Asynchronous Transfer Mode/permanent virtual circuits (ATM/PVCs) feature. It identifies the supported platforms, provides configuration examples, and lists related IOS command line interface (CLI) commands.
This document includes the following major sections:
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Supported Standards, MIBs, and RFCs
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Feature Overview
Network administrators use queueing to manage congestion on a router interface or a permanent virtual circuit (PVC). In an ATM environment, the congestion point might not be the interface itself, but the PVC because of the traffic parameters, including the available bit rate (ABR), the constant bit rate (CBR), and the variable bit rate (VBR) associated with the PVC. For real-time traffic, such as voice flows, to be transmitted in a timely manner, the data rate must not exceed the traffic parameters, or packets might be dropped, thereby affecting voice quality. Fancy queueing such as class-based weighted fair queueing (CBWFQ), low latency queueing (LLQ), or weighted fair queueing (WFQ), can run on the PVC to provide the quality of service (QoS) guarantees for the traffic.
In previous releases, RSVP reservations were not constrained by the traffic parameters of the flow's outbound PVC. As a result, oversubscription could occur when the sum of the RSVP traffic and other traffic exceeded the PVC's capacity.
The RSVP support for ATM/PVCs feature allows RSVP to function with per-PVC queueing for voice-like flows. Specifically, RSVP can install reservations on PVCs defined at the interface and subinterface levels. There is no limit to the number of PVCs that can be configured per interface or subinterface.
RSVP Bandwidth Allocation and Modular QoS Command Line Interface (CLI)
RSVP can use an interface (or a PVC) queueing algorithm, such as WFQ, to ensure QoS for its data flows.
Admission Control
When WFQ is running, RSVP can co-exist with other QoS features on an interface (or PVC) that also reserve bandwidth and enforce QoS. When you configure multiple bandwidth-reserving features (such as RSVP, LLQ, CB-WFQ, and ip rtp priority), portions of the interface's (or PVC's) available bandwidth may be assigned to each of these features for use with flows that they classify.
An internal interface-based (or PVC-based) bandwidth manager prevents the amount of traffic reserved by these features from oversubscribing the interface (or PVC). You can view this pool of available bandwidth using the show queue command, and it is configurable (as a percentage of the interface's or PVC's capacity) via the max-reserved-bandwidth command.
When you configure features such as LLQ and CB-WFQ, any classes that are assigned a bandwidth reserve their bandwidth at the time of configuration, and deduct this bandwidth from the bandwidth manager. If the configured bandwidth exceeds the interface's capacity, the configuration is rejected.
When RSVP is configured, no bandwidth is reserved. (The amount of bandwidth specified in the ip rsvp bandwidth command acts as a strict upper limit, and does not guarantee admission of any flows.) Only when an RSVP reservation arrives does RSVP attempt to reserve bandwidth out of the remaining pool of available bandwidth (that is, the bandwidth that has not been dedicated to traffic handled by other features.)
Data Packet Classification
By default, RSVP performs an efficient flow-based, datapacket classification to ensure QoS for its reserved traffic. This classification runs prior to queueing consideration by ip rtp priority or CB-WFQ. Thus, the use of a CB-WFQ class or ip rtp priority command is not required in order for RSVP data flows to be granted QoS. Any ip rtp priority or CB-WFQ configuration will not match RSVP flows, but they will reserve additional bandwidth for any non-RSVP flows that may match their classifiers.
If you do not want RSVP to perform per-flow classification, but prefer DiffServ classification instead, then you can configure RSVP to exclude itself from data packet classification, and configure LLQ for classification. For more information, see the "RSVP Scalability Enhancements" feature regarding DiffServ integration.
Benefits
Accurate Admission Control
RSVP performs admission control based on the PVC's average cell rate, sustainable cell rate, or minimum cell rate, depending on the type of PVC that is configured, instead of the amount of bandwidth available on the interface.
Recognition of Layer 2 Overhead
RSVP automatically takes the Layer 2 overhead into account when admitting a flow. For each flow, RSVP determines the total amount of bandwidth required, including Layer 2 overhead, and uses this value for admission control with the WFQ bandwidth manager.
Improved QoS
RSVP provides QoS guarantees for high-priority traffic by reserving resources at the point of congestion (that is, the ATM PVC instead of the interface).
Flexible Configurations
RSVP provides support for point-to-point and multipoint interface configurations, thus enabling deployment of services such as voice over IP (VoIP) in ATM environments with QoS guarantees.
Prevention of Bandwidth Oversubscription
RSVP, CBWFQ, and ip rtp priority do not oversubscribe the amount of bandwidth available on the interface or the PVC even when they are running simultaneously. Prior to admitting a reservation, these features check an internal bandwidth manager to avoid oversubscription.
IP QoS Features Integration into ATM Environments
IP QoS features can now be integrated seamlessly from IP into ATM environments with RSVP providing admission control on a per PVC basis.
Restrictions
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Related Features and Technologies
The RSVP support for ATM/PVCs feature is related to QoS features such as low latency queueing and policing. (See the section on "Related Documents".)
Related Documents
The following documents provide additional information:
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Supported Platforms
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Supported Standards, MIBs, and RFCs
Standards
The RSVP support for ATM/PVCs feature supports no new or modified standards.
MIBs
RFC 2206 (RSVP Management Information Base using SMIv2)
To obtain lists of MIBs supported by platform and Cisco IOS release and to download MIB modules, go to the Cisco MIB web site on Cisco.com at http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.
RFCs
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Prerequisites
The network must support the following Cisco IOS features before RSVP support for ATM/PVCs is enabled:
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Configuration Tasks
See the following sections for configuration tasks for the RSVP support for ATM/PVCs feature. Each task in the list indicates whether the task is optional or required.
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Creating a PVC
To create a PVC, use the following command in interface configuration mode:
Router(config-if)# pvc [name] vpi/vci [ilmi | qsaal | smds]
Assigns a name and identifier to a PVC.
Defining ATM QoS Traffic Parameters for a PVC
Note
To configure ATM PVC traffic parameters, use one of the following commands beginning in interface-ATM-VC configuration mode:
The arguments used here are as follows:
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All features running on the PVC, including RSVP, CBWFQ, and LLQ, can use up to 75 percent of the reservable bandwidth pool.
Defining a Policy Map for WFQ
To define a policy map for WFQ, use the following commands, beginning in global configuration mode:
Applying a Policy Map to a PVC
To apply a policy map to a PVC, use the following command, beginning in interface-ATM-VC configuration mode:
Router(config-if-atm-vc)# service-policy output policy-name
Applies a policy map to the output direction of the interface.
Enabling RSVP on an Interface
To enable RSVP on an interface, use the following command in interface configuration mode:
Router(config-if)# ip rsvp bandwidth [interface-kbps] [single-flow-kbps]
Enables RSVP on an interface.
Configuring a Path
To configure an RSVP path, use the following command in global configuration mode:
Configuring a Reservation
To configure an RSVP reservation, use the following command in global configuration mode:
Verifying RSVP Support for ATM/PVCs Configuration
Multipoint Configuration
To verify RSVP support for ATM/PVCs multipoint configuration, use this procedure:
Step 1
Router# show ip rsvp installedRSVP:ATM6/0.1BPS To From Protoc DPort Sport Weight Conversation10K 145.30.30.213 145.40.40.214 UDP 101 101 0 4015K 145.20.20.212 145.40.40.214 UDP 100 100 6 4115K 145.30.30.213 145.40.40.214 UDP 100 100 6 4110K 145.20.20.212 145.40.40.214 UDP 101 101 0 40
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Step 2
Note
Router# show ip rsvp installed detailRSVP:ATM6/0 has the following installed reservationsRSVP:ATM6/0.1 has the following installed reservationsRSVP Reservation. Destination is 145.30.30.213, Source is 145.40.40.214,Protocol is UDP, Destination port is 101, Source port is 101Reserved bandwidth:10K bits/sec, Maximum burst:1K bytes, Peak rate:10K bits/secMin Policed Unit: 0 bytes, Max Pkt Size: 1514Resource provider for this flow:WFQ on ATM PVC 100/101 on AT6/0: PRIORITY queue 40. Weight:0, BW 10 kbpsConversation supports 1 reservationsData given reserved service:0 packets (0M bytes)Data given best-effort service:0 packets (0 bytes)Reserved traffic classified for 48 secondsLong-term average bitrate (bits/sec):0M reserved, 0M best-effortRSVP Reservation. Destination is 145.20.20.212, Source is 145.40.40.214,Protocol is UDP, Destination port is 100, Source port is 100Reserved bandwidth:15K bits/sec, Maximum burst:1K bytes, Peak rate:15K bits/secMin Policed Unit: 0 bytes, Max Pkt Size: 1514Resource provider for this flow:WFQ on ATM PVC 100/201 on AT6/0: RESERVED queue 41. Weight:6, BW 15 kbpsConversation supports 1 reservationsData given reserved service:0 packets (0M bytes)Data given best-effort service:0 packets (0 bytes)Reserved traffic classified for 200 secondsLong-term average bitrate (bits/sec):0M reserved, 0M best-effortRSVP Reservation. Destination is 145.30.30.213, Source is 145.40.40.214,Protocol is UDP, Destination port is 100, Source port is 100Reserved bandwidth:15K bits/sec, Maximum burst:1K bytes, Peak rate:15K bits/secMin Policed Unit: 0 bytes, Max Pkt Size: 1514Resource provider for this flow:WFQ on ATM PVC 100/101 on AT6/0: RESERVED queue 41. Weight:6, BW 15 kbpsConversation supports 1 reservationsData given reserved service:0 packets (0M bytes)Data given best-effort service:0 packets (0 bytes)Reserved traffic classified for 60 secondsLong-term average bitrate (bits/sec):0M reserved, 0M best-effortRSVP Reservation. Destination is 145.20.20.212, Source is 145.40.40.214,Protocol is UDP, Destination port is 101, Source port is 101Reserved bandwidth:10K bits/sec, Maximum burst:1K bytes, Peak rate:10K bits/secMin Policed Unit: 0 bytes, Max Pkt Size: 1514Resource provider for this flow:WFQ on ATM PVC 100/201 on AT6/0: PRIORITY queue 40. Weight:0, BW 10 kbpsConversation supports 1 reservationsData given reserved service:0 packets (0M bytes)Data given best-effort service:0 packets (0 bytes)Reserved traffic classified for 163 secondsLong-term average bitrate (bits/sec):0M reserved, 0M best-effort
Point-to-Point Configuration
To verify RSVP support for ATM/PVCs point-to-point configuration, use this procedure:
Step 1
Router# show ip rsvp installedRSVP:ATM6/0.1BPS To From Protoc DPort Sport Weight Conversation15K 145.30.30.213 145.40.40.214 UDP 100 100 0 4020K 145.30.30.213 145.40.40.214 UDP 101 101 6 41RSVP:ATM6/0.2BPS To From Protoc DPort Sport Weight Conversation150K 145.20.20.212 145.40.40.214 UDP 12 12 6 42Router#
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Router# show ip rsvp installed detailRSVP:ATM6/0 has the following installed reservationsRSVP:ATM6/0.1 has the following installed reservationsRSVP Reservation. Destination is 145.30.30.213, Source is 145.40.40.214,Protocol is UDP, Destination port is 101, Source port is 101Reserved bandwidth:15K bits/sec, Maximum burst:1K bytes, Peak rate:15K bits/secMin Policed Unit: 0 bytes, Max Pkt Size: 1514 bytesResource provider for this flow:WFQ on ATM PVC 100/101 on AT6/0: PRIORITY queue 40. Weight:0, BW 15 kbpsConversation supports 1 reservationsData given reserved service:0 packets (0M bytes)Data given best-effort service:0 packets (0 bytes)Reserved traffic classified for 48 secondsLong-term average bitrate (bits/sec):0M reserved, 0M best-effortRSVP Reservation. Destination is 145.20.20.212, Source is 145.40.40.214,Protocol is UDP, Destination port is 100, Source port is 100Reserved bandwidth:15K bits/sec, Maximum burst:1K bytes, Peak rate:15K bits/secMin Policed Unit: 0 bytes, Max Pkt Size: 1514 bytesResource provider for this flow:WFQ on ATM PVC 100/201 on AT6/0: RESERVED queue 41. Weight:6, BW 15 kbpsConversation supports 1 reservationsData given reserved service:0 packets (0M bytes)Data given best-effort service:0 packets (0 bytes)Reserved traffic classified for 200 secondsLong-term average bitrate (bits/sec):0M reserved, 0M best-effortRSVP Reservation. Destination is 145.30.30.213, Source is 145.40.40.214,Protocol is UDP, Destination port is 100, Source port is 100Reserved bandwidth:20K bits/sec, Maximum burst:1K bytes, Peak rate:20K bits/secMin Policed Unit: 0 bytes, Max Pkt Size: 1514 bytesResource provider for this flow:WFQ on ATM PVC 100/101 on AT6/0: RESERVED queue 41. Weight:6, BW 20 kbpsConversation supports 1 reservationsData given reserved service:0 packets (0M bytes)Data given best-effort service:0 packets (0 bytes)Reserved traffic classified for 60 secondsLong-term average bitrate (bits/sec):0M reserved, 0M best-effortRSVP:ATM6/0.2 has the following installed reservationsRSVP Reservation. Destination is 145.20.20.212, Source is 145.40.40.214,Protocol is UDP, Destination port is 101, Source port is 101Reserved bandwidth:150K bits/sec, Maximum burst:1K bytes, Peak rate:150K bits/secMin Policed Unit: 0 bytes, Max Pkt Size: 1514 bytesResource provider for this flow:WFQ on ATM PVC 100/201 on AT6/0: PRIORITY queue 40. Weight:0, BW 150 kbpsConversation supports 1 reservationsData given reserved service:0 packets (0M bytes)Data given best-effort service:0 packets (0 bytes)Reserved traffic classified for 163 secondsLong-term average bitrate (bits/sec):0M reserved, 0M best-effort
Monitoring and Maintaining RSVP Support for ATM/PVCs
To monitor and maintain RSVP support for ATM/PVCs, use the following commands in EXEC mode:
Configuration Examples
This section provides point-to-point and multipoint configuration examples for the RSVP support for ATM/PVCs feature.
Point-to-Point Configuration
Figure 1 shows a sample point-to-point interface configuration commonly used in ATM environments in which one PVC per subinterface is configured at router R1.
Three small clouds represent office branches that are connected through PVCs over an ATM network.
Figure 1 Point-to-Point Interface Configuration
Here is sample output for a point-to-point configuration:
Router#policy-map wfq-voipclass class-defaultfair-queueinterface ATM6/0no ip addressip rsvp bandwidth 112320 112320interface ATM6/0.1 point-to-pointip address 10.1.1.1 255.0.0.0pvc green 100/101vbr-rt 400 300 200inarp 1broadcastservice-policy output wfq-voipip rsvp bandwidth 1250 1250ip rsvp resource-provider wfq pvcinterface ATM6/0.2 point-to-pointip address 10.3.1.1 255.0.0.0pvc yellow 100/201vbr-nrt 500 400 1000inarp 1broadcastservice-policy output wfq-voipip rsvp bandwidth 1250 1250ip rsvp resource-provider wfq pvcMultipoint Configuration
Figure 2 shows a multipoint interface configuration commonly used in ATM environments in which multiple PVCs are configured on the same subinterface at router R1.
The customer enterprise network that includes R1 is the headquarters of a company with PVC connections to each remote office.
Figure 2 Multipoint Interface Configuration
Here is sample output for a multipoint configuration:
Router#policy-map wfq-voipclass class-defaultfair-queueinterface ATM6/0no ip addressip rsvp bandwidth 112320 112320interface ATM6/0.1 multipointip address 10.1.1.1 255.0.0.0pvc green 100/101vbr-rt 400 300 200inarp 1broadcastservice-policy output wfq-voippvc yellow 100/201vbr-nrt 500 400 1000inarp 1broadcastservice-policy output wfq-voipip rsvp bandwidth 1250 1250ip rsvp resource-provider wfq pvcCommand Reference
This section describes five CLI commands that you can use with the RSVP support for ATM/PVCs feature:
All other commands used with this feature are documented in the Cisco IOS Release10.0, 11.0, and 12.0 command reference publications.
ip rsvp layer2 overhead
To control the overhead accounting performed by RSVP/WFQ when a flow is admitted onto an ATM PVC, use the ip rsvp layer2 overhead interface configuration command. To disable the ip rsvp layer2 overhead interface configuration command, use the no form of this command.
ip rsvp layer2 overhead [h c n]
no ip rsvp layer2 overhead
Syntax Description
Defaults
This command is enabled by default on ATM interfaces that are running RSVP and WFQ. You can also use this command on non-ATM interfaces.
The default version of the command, which you specify by entering the default prefix, default ip rsvp layer2 overhead, or by omitting the parameters (h, c, and n) and entering ip rsvp layer2 overhead causes RSVP to determine the overhead values automatically, based on the interface/PVC encapsulation. (Currently, RSVP recognizes ATM Adaptation Layer 5 (AAL5) subnetwork access protocol (SNAP) and MUX encapsulations.)
On non-ATM/PVC interfaces, the configured h, c, and n parameters determine the values that RSVP uses for its overhead.
Command Modes
Interface configuration
Command History
Usage Guidelines
When an IP flow traverses a link, the overhead of Layer 2 encapsulation can increase the amount of bandwidth that the flow requires to exceed the advertised (Layer 3) rate.
In many cases, the additional bandwidth a flow requires due to Layer 2 overhead is negligible and can be transmitted as part of the 25 percent of the link, which is unreservable and kept for routing updates and Layer 2 overhead. This is typically true when the IP flow uses large packet sizes or when the Layer 2 encapsulation allows for frames of variable size (such as in Ethernet and Frame Relay encapsulations).
However, when a flow's packet sizes are small and the underlying Layer 2 encapsulation uses fixed-size frames, the Layer 2 encapsulation overhead can be significant. This is usually the case when VoIP flows traverse ATM links.
To avoid oversubscribing ATM PVCs, which use AAL5 SNAP or AAL5 MUX encapsulations, RSVP automatically accounts for the Layer 2 overhead when admitting a flow. For each flow, RSVP determines the total amount of bandwidth required, including Layer 2 overhead, and uses this value for admission control with the WFQ bandwidth manager.
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Examples
In the following example, the total amount of bandwidth reserved with WFQ appears:
Router# show ip rsvp installed detailRSVP:ATM6/0 has the following installed reservationsRSVP Reservation. Destination is 11.1.1.1, Source is 10.1.1.1,Protocol is UDP, Destination port is 1000, Source port is 1000Reserved bandwidth:50K bits/sec, Maximum burst:1K bytes, Peak rate:50K bits/secMin Policed Unit:60 bytes, Max Pkt Size:60 bytesResource provider for this flow:WFQ on ATM PVC 100/101 on AT6/0: PRIORITY queue 40. Weight:0, BW 89 kbpsConversation supports 1 reservationsData given reserved service:0 packets (0M bytes)Data given best-effort service:0 packets (0 bytes)Reserved traffic classified for 9 secondsLong-term average bitrate (bits/sec):0M reserved, 0M best-effortRouter#In the preceding example, the flow's advertised Layer 3 rate is 50 kbps. This value is used for admission control with the ip rsvp bandwidth value. The actual bandwidth required, inclusive of Layer 2 overhead, is 89 kbps. WFQ uses this value for admission control.
Typically, you should not need to configure or disable the Layer 2 overhead accounting. RSVP uses the advertised Layer 3 flow rate, minimum packet size, and maximum unit size in conjunction with the Layer 2 encapsulation characteristics of the ATM PVC to compute the required bandwidth for admission control. However, you can disable or customize the Layer 2 overhead accounting (for any link type) with the ip rsvp layer2 overhead command. The parameters of this command are based on the following steps that show how a Layer 3 packet is fragmented and encapsulated for Layer 2 transmission:
Step 1
Figure 3 Layer 3 Packet
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Figure 4 Layer 3 Packet with Layer 2 Header
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Figure 5 Segmented Packet
Step 4
More Configuration Examples
In the following example, Layer 2 overhead accounting is disabled for all reservations on the interface and its PVCs:
Router(config-if)# no ip rsvp layer2 overheadIn the following example, Layer 2 overhead accounting is configured with ATM AAL5 SNAP encapsulation:
Router(config-if)# no ip rsvp layer2 overhead 8 5 48In the following example, Layer 2 overhead accounting is configured with ATM AAL5 MUX encapsulation:
Router(config-if)# ip rsvp layer2 overhead 0 5 48In the following example, Layer 2 overhead accounting is configured with Ethernet V2.0 encapsulation (including 8-byte preamble, 6-byte source-active (SA) messages, 6-byte destination-active (DA) messages, 2-byte type, and 4-byte frame check sequence (FCS) trailer):
Router(config-if)# ip rsvp layer2 overhead 26 0 1500Related Commands
ip rsvp resource-provider
To configure a resource provider for an aggregate flow, use the ip rsvp resource-provider interface configuration command. To disable the ip rsvp resource-provider interface configuration command, use the no form of the command.
ip rsvp resource-provider {none | wfq interface | wfq pvc}
no ip rsvp resource-provider
Syntax Description
Defaults
This command has no default behavior or values.
Command Modes
Interface configuration
Command History
Usage Guidelines
Use the ip rsvp resource-provider command with the wfq pvc argument in ATM/PVC environments. To ensure that a flow receives QoS, WFQ has to be running on the PVC or reservations fail.
Examples
Here is an example of the ip rsvp resource-provider command:
Router# configure terminalRouter(config)# int atm6/0Router(config-if)# ip rsvp resource-provider wfq pvcRouter(config-if)#Related Commands
show ip rsvp installed
To display information about interfaces and their admitted reservations, use the show ip rsvp installed EXEC command.
show ip rsvp installed [detail]
Syntax Description
detail
(Optional) Specifies additional information about interfaces and their reservations, including the Layer 2 bandwidth field.
Defaults
No default behavior or values.
Command Modes
EXEC
Command History
Usage Guidelines
The show ip rsvp installed command displays information about interfaces and their reservations. Enter the optional keyword, detail, for additional information, including the reservation's traffic parameters, downstream hop, and resources that RSVP uses to ensure QoS for this reservation.
Examples
Here is sample output from the show ip rsvp installed command on an ATM interface:
Router# show ip rsvp installedRSVP:ATM6/0BPS To From Protoc DPort Sport Weight Conversation15K 145.20.20.212 145.10.10.211 UDP 14 14 6 7420K 145.20.20.212 145.10.10.211 UDP 10 10 6 72Router#Table 1 describes the fields in the preceding output.
Here is sample output from the show ip rsvp installed detail command on an ATM interface:
Router# show ip rsvp installed detailRSVP: ATM6/0 has the following installed reservationsRSVP Reservation. Destination is 145.20.20.212, Source is 145.10.10.211,Protocol is UDP, Destination port is 14, Source port is 14Reserved bandwidth: 50K bits/sec, Maximum burst: 1K bytes, Peak rate: 50K bits/secMin Policed Unit: 0 bytes, Max Pkt Size: 1514 bytesResource provider for this flow:WFQ on ATM PVC 200/100 on AT6/0: RESERVED queue 74. Weight: 6, BW 50 kbpsConversation supports 1 reservationsData given reserved service: 227 packets (110776 bytes)Data given best-effort service: 1 packets (488 bytes)Reserved traffic classified for 17 secondsLong-term average bitrate (bits/sec): 50571 reserved, 222 best-effortRSVP Reservation. Destination is 145.20.20.212, Source is 145.10.10.211,Protocol is UDP, Destination port is 10, Source port is 10Reserved bandwidth: 20K bits/sec, Maximum burst: 1K bytes, Peak rate: 20K bits/secMin Policed Unit: 0 bytes, Max Pkt Size: 1514 bytesResource provider for this flow:WFQ on ATM PVC 200/100 on AT6/0: PRIORITY queue 72. Weight: 0, BW 20 kbpsConversation supports 1 reservationsData given reserved service: 202 packets (98576 bytes)Data given best-effort service: 0 packets (0 bytes)Reserved traffic classified for 40 secondsLong-term average bitrate (bits/sec): 19523 reserved, 0M best-effortshow ip rsvp interface
To display RSVP-related interface information, use the show ip rsvp interface EXEC command.
show ip rsvp interface [interface-type interface-number] [detail]
Syntax Description
interface-type
(Optional) The type of the interface.
interface-number
(Optional) The number of the interface.
detail
(Optional) Specifies additional information about interfaces.
Defaults
No default behavior or values.
Command Modes
EXEC
Command History
11.2
This command was introduced.
12.2(2)T
This command was modified to include the keyword, detail.
Usage Guidelines
Use the show ip rsvp interface command to display the current bandwidth allocation budget and maximum available bandwidth. Enter the optional keyword, detail, for additional information, including a resource provider, if you configured one.
Examples
In the following output from the show ip rsvp interface command, a flow of 15 kbps is admitted on subinterface AT6/0.1:
Router# show ip rsvp interfaceinterface allocated i/f max flow max pct UDP IP UDP_IP UDP M/CAT6/0 15K 116250K 116250K 0 0 0 0 0AT6/0.1 15K 1250K 1250K 2 0 1 0 0AT6/0.2 0M 1250K 1250K 0 0 1 0 0Table 2 describes the fields in the preceding output.
Here is sample output from the show ip rsvp interface detail command showing that no resource provider has been configured:
Router# show ip rsvp interface detailAT6/0:Bandwidth:Curr allocated: 190K bits/secMax. allowed (total): 112320K bits/secMax. allowed (per flow): 112320K bits/secNeighbors:Using IP encap: 1. Using UDP encaps: 0DSCP value used in Path/Resv msgs: 0x30show queueing
To display the current state of the queues, use the show queueing EXEC command.
show queueing [custom | fair | priority | random-detect [ interface serial-number]]
Syntax Description
Defaults
Fair queueing configuration
Command Modes
EXEC
Command History
Usage Guidelines
Use the show queueing command to verify that RSVP, CBWFQ, and ip rtp priority contact the bandwidth manager. Initiate RSVP flows by using the ip rsvp sender and the ip rsvp reservation commands and verify that the value in the last line of the following output (available bandwidth) decreases as RSVP flows are admitted.
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Examples
In the following output, the available bandwidth on the ATM6/0 VC 100/101 interface is 225 kbps:
Router# show queueing interface atm6/0Interface ATM6/0 VC 0/5Queueing strategy: fifoOutput queue 0/40, 0 drops per VCInterface ATM6/0 VC 0/16Queueing strategy: fifoOutput queue 0/40, 0 drops per VCInterface ATM6/0 VC 100/101Queueing strategy: weighted fairTotal output drops per VC: 0Output queue: 0/512/64/0 (size/max total/threshold/drops)Conversations 0/1/32 (active/max active/max total)Reserved Conversations 0/0 (allocated/max allocated)Available Bandwidth 225 kilobits/secInterface ATM6/0 VC 100/201Queueing strategy: weighted fairTotal output drops per VC: 0Output queue: 0/512/64/0 (size/max total/threshold/drops)Conversations 0/1/32 (active/max active/max total)Reserved Conversations 0/1 (allocated/max allocated)Available Bandwidth 300 kilobits/secAdmit a flow of 15 kbps on the AT6/0.1 subinterface:
Router# show ip rsvp interfaceinterface allocated i/f max flow max pct UDP IP UDP_IP UDP M/CAT6/0 15K 116250K 116250K 0 0 0 0 0AT6/0.1 15K 1250K 1250K 2 0 1 0 0AT6/0.2 0M 1250K 1250K 0 0 1 0 0Notice that the available bandwidth on the ATM6/0 VC 100/101 interface decreases from 225 kbps to 210 kbps:
Router# show queueing interface atm6/0Interface ATM6/0 VC 0/5Queueing strategy: fifoOutput queue 0/40, 0 drops per VCInterface ATM6/0 VC 0/16Queueing strategy: fifoOutput queue 0/40, 0 drops per VCInterface ATM6/0 VC 100/101Queueing strategy: weighted fairTotal output drops per VC: 0Output queue: 0/512/64/0 (size/max total/threshold/drops)Conversations 0/1/32 (active/max active/max total)Reserved Conversations 0/0 (allocated/max allocated)Available Bandwidth 210 kilobits/secInterface ATM6/0 VC 100/201Queueing strategy: weighted fairTotal output drops per VC: 0Output queue: 0/512/64/0 (size/max total/threshold/drops)Conversations 0/1/32 (active/max active/max total)Reserved Conversations 0/1 (allocated/max allocated)Available Bandwidth 300 kilobits/secDebug Commands
This section describes the debug commands that are related to the RSVP support for ATM/PVC feature:
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debug ip rsvp traffic-control
To display debug messages for traffic control, use the debug ip rsvp traffic-control EXEC command. To disable the debug ip rsvp traffic-control command, use the no form of this command.
[no] debug ip rsvp traffic-control
Syntax Description
This command has no arguments or keywords.
Defaults
No default behavior or values.
Command History
Examples
Here is an example of output from the debug ip rsvp traffic-control command:
Router# debug ip rsvp traffic-controlRSVP debugging is onRouter# show debuggingIP RSVP debugging is onIP RSVP debugging (Traffic Control events) is onRouter#The following output is from a successful allocation:
1w4d:RSVP-TC:Attempting to install QoS for rsb 62E2497C1w4d:RSVP-TC:Adding new tcsb 0001A801 for rsb 62E2497C1w4d:RSVP-TC:Assigning WFQ QoS (on ATM VC 100/101) to tcsb 0001A8011w4d:RSVP-TC:Consulting policy for tcsb 0001A8011w4d:RSVP-TC:Policy granted QoS for tcsb 0001A8011w4d:RSVP-TC:Requesting QoS for tcsb 0001A8011w4d:RSVP-TC: ( r = 1875 bytes/s M = 1514 bytes1w4d:RSVP-TC: b = 1000 bytes m = 0 bytes )1w4d:RSVP-TC: p = 1875 bytes/s Service Level = priority1w4d:RSVP-TC:Allocation succeeded for tcsb 0001A801The following output is from an unsuccessful allocation:
1w4d:RSVP-TC:Attempting to install QoS for rsb 62E66A841w4d:RSVP-TC:Adding new tcsb 0001EB01 for rsb 62E66A841w4d:RSVP-TC:Assigning WFQ QoS (on ATM VC 100/101) to tcsb 0001EB011w4d:RSVP-TC:Consulting policy for tcsb 0001EB011w4d:RSVP-TC:Policy granted QoS for tcsb 0001EB011w4d:RSVP-TC:Requesting QoS for tcsb 0001EB011w4d:RSVP-TC: ( r = 31250 bytes/s M = 1514 bytes1w4d:RSVP-TC: b = 1000 bytes m = 0 bytes )1w4d:RSVP-TC: p = 31250 bytes/s Service Level = non-priority1w4d:RSVP-TC:Allocation failed for tcsb 0001EB01Related Commands
debug ip rsvp wfq
To display debug messages for weighted fair queueing (WFQ), use the debug ip rsvp wfq EXEC command. To disable the debug ip rsvp wfq command, use the no form of this command.
[no] debug ip rsvp wfq
Syntax Description
This command has no arguments or keywords.
Defaults
No default behavior or values.
Command History
Examples
Here is an example of output from the debug ip rsvp wfq command:
Router# show debuggingRouter# debug ip rsvp wfqRSVP debugging is onRouter# show debuggingIP RSVP debugging is onIP RSVP debugging (Traffic Control events) is onIP RSVP debugging (WFQ events) is onRouter#The following output is from a successful allocation with Layer 2 overhead accounting disabled:
1w4d:RSVP-TC:Attempting to install QoS for rsb 62E60CD81w4d:RSVP-TC:Adding new tcsb 00021C01 for rsb 62E60CD81w4d:RSVP-TC:Assigning WFQ QoS (on ATM VC 100/101) to tcsb 00021C011w4d:RSVP-TC:Consulting policy for tcsb 00021C011w4d:RSVP-TC:Policy granted QoS for tcsb 00021C011w4d:RSVP-TC:Requesting QoS for tcsb 00021C011w4d:RSVP-TC: ( r = 1875 bytes/s M = 1514 bytes1w4d:RSVP-TC: b = 1000 bytes m = 0 bytes )1w4d:RSVP-TC: p = 1875 bytes/s Service Level = priority1w4d:RSVP-WFQ:Update for tcsb 00021C01 on ATM PVC 100/101 on AT6/01w4d:RSVP-WFQ:Admitted 15 kbps of bandwidth1w4d:RSVP-WFQ:Allocated PRIORITY queue 401w4d:RSVP-TC:Allocation succeeded for tcsb 00021C01The following output is from an unsuccessful allocation with Layer 2 overhead accounting disabled:
1w4d:RSVP-TC:Attempting to install QoS for rsb 62E66A841w4d:RSVP-TC:Adding new tcsb 00024101 for rsb 62E66A841w4d:RSVP-TC:Assigning WFQ QoS (on ATM VC 100/101) to tcsb 000241011w4d:RSVP-TC:Consulting policy for tcsb 000241011w4d:RSVP-TC:Policy granted QoS for tcsb 000241011w4d:RSVP-TC:Requesting QoS for tcsb 000241011w4d:RSVP-TC: ( r = 43750 bytes/s M = 1514 bytes1w4d:RSVP-TC: b = 1000 bytes m = 0 bytes )1w4d:RSVP-TC: p = 43750 bytes/s Service Level = non-priority1w4d:RSVP-WFQ:Update for tcsb 00024101 on ATM PVC 100/101 on AT6/01w4d:RSVP-WFQ:FAILURE -- 350 kbps of bandwidth unavailable1w4d:RSVP-TC:Allocation failed for tcsb 000241011w4d:RSVP-TC:Deleting tcsb 00024101The following output is from a successful allocation with Layer 2 overhead accounting enabled:
2d05h:RSVP-TC:Attempting to install QoS for rsb 63546A942d05h:RSVP-TC:Adding new tcsb 0007800A for rsb 63546A942d05h:RSVP-TC:Assigning WFQ resource provider (on ifc) to tcsb 0007800A2d05h:RSVP-TC:Consulting policy for tcsb 0007800A2d05h:RSVP-TC:Policy granted QoS for tcsb 0007800A2d05h:RSVP-TC:Requesting QoS for tcsb 0007800A2d05h:RSVP-TC: ( r = 2860 bytes/s M = 52 bytes2d05h:RSVP-TC: b = 208 bytes m = 52 bytes )2d05h:RSVP-TC: p = 3146 bytes/s Service Level = priority2d05h:RSVP-WFQ:Update for tcsb 0007800A on hw idb Et3/32d05h:RSVP-WFQ:Admitted 47 kbps of bandwidth
Note
Related Commands
Glossary
AAL—ATM adaptation layer. AAL defines the conversion of user information into cells. AAL1 and AAL2 handle isochronous traffic, such as voice and video; AAL3/4 and AAL5 pertain to data communications through the segmentation and reassembly of packets.
ABR—Available bit rate. A QoS class defined by the ATM Forum for ATM networks. ABR is used for connections that do not require timing relationships between source and destination. ABR provides no guarantees in terms of cell loss or delay, providing only best-effort service. Traffic sources adjust their transmission rate in response to information they receive describing the status of the network and its capability to successfully deliver data.
admission control—The process in which an RSVP reservation is accepted or rejected based on end-to-end available network resources.
Asynchronous Transfer Mode—See ATM.
ATM—Asynchronous Transfer Mode. A cell-based data transfer technique in which channel demand determines packet allocation. This is an international standard for cell relay in which multiple service types (such as voice, video, or data) are conveyed in fixed-length (53-byte) cells. Fixed-length cells allow cell processing to occur in hardware, thereby reducing transit delays. ATM is designed to take advantage of high-speed transmission media such as E3, SONET, and T3.
available bit rate—See ABR.
bandwidth—The difference between the highest and lowest frequencies available for network signals. This term also describes the rated throughput capacity of a given network medium or protocol.
CBR—Constant bit rate. A QoS class defined by the ATM Forum for ATM networks. CBR is used for connections that depend on precise clocking to ensure undistorted delivery.
CBWFQ—Class-based weighted fair queueing. A queueing mechanism that extends the standard WFQ functionality to provide support for user-defined traffic classes.
Class-based weighted fair queueing—See CBWFQ.
constant bit rate—See CBR.
flow—A stream of data traveling between two endpoints across a network (for example, from one LAN station to another). Multiple flows can be transmitted on a single circuit.
ILMI—Interim Local Management Interface. Described in the ATM Forum's UNI specification, ILMI allows end users to retrieve basic information, such as status and configuration about virtual connections and addresses, for a particular UNI.
Interim Local Management Interface—See ILMI.
latency—The delay between the time a device receives a packet and the time that the packet is forwarded out the destination port.
MUX—A multiplexing device that combines multiple signals for transmission over a single line. The signals are demultiplexed, or separated, at the receiving end.
payload—The portion of a cell, frame, or packet that contains upper-layer information (data).
permanent virtual circuit—See PVC.
point-to-multipoint connection—One of two fundamental connection types. It is a unidirectional connection in which a single source end system (known as a root node) connects to multiple destination end systems (known as leaves).
point-to-point connection—One of two fundamental connection types. It is a unidirectional or bidirectional connection between two end systems.
PQ—Priority queue. A routing feature in which frames in an output queue are assigned priority based on various characteristics such as packet size and interface type.
priority queue—See PQ.
PVC—Permanent virtual circuit or connection. A virtual circuit that is permanently established. PVCs save bandwidth associated with circuit establishment and teardown in situations where certain virtual circuits must exist all the time.
QoS—Quality of service. A measure of performance for a transmission system that reflects its transmission quality and service availability.
quality of service—See QoS.
reservable bandwidth pool—The amount of bandwidth on a link that features can set aside in order to provide QoS guarantees.
Resource Reservation Protocol—See RSVP.
RSVP—Resource Reservation Protocol. A protocol for reserving network resources to provide quality of service guarantees to application flows.
SNAP—Subnetwork Access Protocol. An Internet protocol that operates between a network entity in the subnetwork and a network entity in the end system. SNAP specifies a standard method of encapsulating IP datagrams and ARP messages on IEEE networks. The SNAP entity in the end system makes use of the services of the subnetwork and performs three key functions: data transfer, connection management, and QoS selection.
subnetwork access protocol—See SNAP.
SVC—Switched virtual circuit or connection. A virtual circuit that is dynamically established on demand and is torn down when transmission is complete. SVCs are used in situations where data transmission is sporadic.
switched virtual circuit—See SVC.
variable bit rate—See VBR.
VBR—Variable bit rate. A QoS class defined by the ATM Forum for ATM networks. VBR is subdivided into a real time (RT) class and a non-real time (NRT) class. VBR (RT) is used for connections in which there is a fixed timing relationship between samples. VBR (NRT) is used for connections where there is no fixed timing relationship between samples, but where a guaranteed QoS is still needed.
VC—Virtual circuit. A logical circuit created to ensure reliable communication between two network devices. A virtual circuit can be either permanent (PVC) or switched (SVC).
virtual circuit—See VC.
Voice over IP—See VoIP.
VoIP—Voice over IP. The ability to carry normal telephony-style voice over an IP-based internet maintaining telephone-like functionality, reliability, and voice quality.
weighted fair queueing—See WFQ.
WFQ—Weighted fair queueing. A queue management algorithm that provides a certain fraction of link bandwidth to each of several queues, based on relative bandwidth applied to each of the queues.
